Opposition Foreign Affairs spokeswoman Tanya Plibersek has slammed the Government over the amount of money it is donating to an international fund to fight communicable diseases.

Donors to the Global Fund to fight AIDS, tuberculosis and malaria have just finished their meeting in Washington and have pledged more money for the next three years.

The fund is a public-private partnership and one of the most successful organisations of its type in the world.

Aid groups had expected Australia would donate $375 million, but it is donating $200 million.

Last year, the then-Labor government committed $100 million to the fund.

"Certainly there was an expectation that the amount would grow," Ms Plibersek told AM.

"The funding next year will be $67 million - a very substantial drop in funding for an organisation that is having success in fighting HIV, tuberculosis and malaria. If we don't invest now we will pay forever."

World Vision Australia CEO Tim Costello says he is very disappointed.

"The truth is that we should have been giving about $125 million a year and it's been reduced to $67 million," he said.

"I know a lot of Australians will say, oh yes, but we've got our own crises. Let's put it in perspective. We are number one out of 215 nations in the median per capita wealth. We're the wealthiest. Switzerland comes second. So we are blessed.

"And to defeat tuberculosis, HIV and malaria, which literally saves lives, is in our interests because we know that drug resistant tuberculosis is jumping from Papua New Guinea to northern Queensland.

"So it's a wise investment because it saves lives of others and it helps protects Australians."

Cutting funding to Australia's region 'not a good look'

Ms Plibersek says maintaining or increasing Australia's contribution to the Global Fund is a sign of being a good world citizen.

"I think it's important that Australia shows leadership. It's very difficult to expect countries poorer than Australia to keep up their commitments when we're cutting our commitments," she said.

Ms Costello says those cuts will affect Australia's standing.

"When you cut aid in the region where most of the world's poor live - our neighbourhood, Asia - it's not a good look," he said.